linux_dsm_epyc7002/arch/s390/mm/vmem.c
Heiko Carstens 5a79859ae0 s390: remove 31 bit support
Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e58 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-03-25 11:49:33 +01:00

417 lines
9.3 KiB
C

/*
* Copyright IBM Corp. 2006
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#include <linux/bootmem.h>
#include <linux/pfn.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <linux/memblock.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/setup.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
static DEFINE_MUTEX(vmem_mutex);
struct memory_segment {
struct list_head list;
unsigned long start;
unsigned long size;
};
static LIST_HEAD(mem_segs);
static void __ref *vmem_alloc_pages(unsigned int order)
{
if (slab_is_available())
return (void *)__get_free_pages(GFP_KERNEL, order);
return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
}
static inline pud_t *vmem_pud_alloc(void)
{
pud_t *pud = NULL;
pud = vmem_alloc_pages(2);
if (!pud)
return NULL;
clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
return pud;
}
static inline pmd_t *vmem_pmd_alloc(void)
{
pmd_t *pmd = NULL;
pmd = vmem_alloc_pages(2);
if (!pmd)
return NULL;
clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
return pmd;
}
static pte_t __ref *vmem_pte_alloc(unsigned long address)
{
pte_t *pte;
if (slab_is_available())
pte = (pte_t *) page_table_alloc(&init_mm);
else
pte = alloc_bootmem_align(PTRS_PER_PTE * sizeof(pte_t),
PTRS_PER_PTE * sizeof(pte_t));
if (!pte)
return NULL;
clear_table((unsigned long *) pte, _PAGE_INVALID,
PTRS_PER_PTE * sizeof(pte_t));
return pte;
}
/*
* Add a physical memory range to the 1:1 mapping.
*/
static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
{
unsigned long end = start + size;
unsigned long address = start;
pgd_t *pg_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
pte_t *pt_dir;
int ret = -ENOMEM;
while (address < end) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
pu_dir = vmem_pud_alloc();
if (!pu_dir)
goto out;
pgd_populate(&init_mm, pg_dir, pu_dir);
}
pu_dir = pud_offset(pg_dir, address);
#ifndef CONFIG_DEBUG_PAGEALLOC
if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
!(address & ~PUD_MASK) && (address + PUD_SIZE <= end)) {
pud_val(*pu_dir) = __pa(address) |
_REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE |
(ro ? _REGION_ENTRY_PROTECT : 0);
address += PUD_SIZE;
continue;
}
#endif
if (pud_none(*pu_dir)) {
pm_dir = vmem_pmd_alloc();
if (!pm_dir)
goto out;
pud_populate(&init_mm, pu_dir, pm_dir);
}
pm_dir = pmd_offset(pu_dir, address);
#ifndef CONFIG_DEBUG_PAGEALLOC
if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
!(address & ~PMD_MASK) && (address + PMD_SIZE <= end)) {
pmd_val(*pm_dir) = __pa(address) |
_SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE |
_SEGMENT_ENTRY_YOUNG |
(ro ? _SEGMENT_ENTRY_PROTECT : 0);
address += PMD_SIZE;
continue;
}
#endif
if (pmd_none(*pm_dir)) {
pt_dir = vmem_pte_alloc(address);
if (!pt_dir)
goto out;
pmd_populate(&init_mm, pm_dir, pt_dir);
}
pt_dir = pte_offset_kernel(pm_dir, address);
pte_val(*pt_dir) = __pa(address) |
pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
address += PAGE_SIZE;
}
ret = 0;
out:
return ret;
}
/*
* Remove a physical memory range from the 1:1 mapping.
* Currently only invalidates page table entries.
*/
static void vmem_remove_range(unsigned long start, unsigned long size)
{
unsigned long end = start + size;
unsigned long address = start;
pgd_t *pg_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
pte_t *pt_dir;
pte_t pte;
pte_val(pte) = _PAGE_INVALID;
while (address < end) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
address += PGDIR_SIZE;
continue;
}
pu_dir = pud_offset(pg_dir, address);
if (pud_none(*pu_dir)) {
address += PUD_SIZE;
continue;
}
if (pud_large(*pu_dir)) {
pud_clear(pu_dir);
address += PUD_SIZE;
continue;
}
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
address += PMD_SIZE;
continue;
}
if (pmd_large(*pm_dir)) {
pmd_clear(pm_dir);
address += PMD_SIZE;
continue;
}
pt_dir = pte_offset_kernel(pm_dir, address);
*pt_dir = pte;
address += PAGE_SIZE;
}
flush_tlb_kernel_range(start, end);
}
/*
* Add a backed mem_map array to the virtual mem_map array.
*/
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
{
unsigned long address = start;
pgd_t *pg_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
pte_t *pt_dir;
int ret = -ENOMEM;
for (address = start; address < end;) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
pu_dir = vmem_pud_alloc();
if (!pu_dir)
goto out;
pgd_populate(&init_mm, pg_dir, pu_dir);
}
pu_dir = pud_offset(pg_dir, address);
if (pud_none(*pu_dir)) {
pm_dir = vmem_pmd_alloc();
if (!pm_dir)
goto out;
pud_populate(&init_mm, pu_dir, pm_dir);
}
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
/* Use 1MB frames for vmemmap if available. We always
* use large frames even if they are only partially
* used.
* Otherwise we would have also page tables since
* vmemmap_populate gets called for each section
* separately. */
if (MACHINE_HAS_EDAT1) {
void *new_page;
new_page = vmemmap_alloc_block(PMD_SIZE, node);
if (!new_page)
goto out;
pmd_val(*pm_dir) = __pa(new_page) |
_SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE;
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
pt_dir = vmem_pte_alloc(address);
if (!pt_dir)
goto out;
pmd_populate(&init_mm, pm_dir, pt_dir);
} else if (pmd_large(*pm_dir)) {
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
pt_dir = pte_offset_kernel(pm_dir, address);
if (pte_none(*pt_dir)) {
void *new_page;
new_page = vmemmap_alloc_block(PAGE_SIZE, node);
if (!new_page)
goto out;
pte_val(*pt_dir) =
__pa(new_page) | pgprot_val(PAGE_KERNEL);
}
address += PAGE_SIZE;
}
ret = 0;
out:
return ret;
}
void vmemmap_free(unsigned long start, unsigned long end)
{
}
/*
* Add memory segment to the segment list if it doesn't overlap with
* an already present segment.
*/
static int insert_memory_segment(struct memory_segment *seg)
{
struct memory_segment *tmp;
if (seg->start + seg->size > VMEM_MAX_PHYS ||
seg->start + seg->size < seg->start)
return -ERANGE;
list_for_each_entry(tmp, &mem_segs, list) {
if (seg->start >= tmp->start + tmp->size)
continue;
if (seg->start + seg->size <= tmp->start)
continue;
return -ENOSPC;
}
list_add(&seg->list, &mem_segs);
return 0;
}
/*
* Remove memory segment from the segment list.
*/
static void remove_memory_segment(struct memory_segment *seg)
{
list_del(&seg->list);
}
static void __remove_shared_memory(struct memory_segment *seg)
{
remove_memory_segment(seg);
vmem_remove_range(seg->start, seg->size);
}
int vmem_remove_mapping(unsigned long start, unsigned long size)
{
struct memory_segment *seg;
int ret;
mutex_lock(&vmem_mutex);
ret = -ENOENT;
list_for_each_entry(seg, &mem_segs, list) {
if (seg->start == start && seg->size == size)
break;
}
if (seg->start != start || seg->size != size)
goto out;
ret = 0;
__remove_shared_memory(seg);
kfree(seg);
out:
mutex_unlock(&vmem_mutex);
return ret;
}
int vmem_add_mapping(unsigned long start, unsigned long size)
{
struct memory_segment *seg;
int ret;
mutex_lock(&vmem_mutex);
ret = -ENOMEM;
seg = kzalloc(sizeof(*seg), GFP_KERNEL);
if (!seg)
goto out;
seg->start = start;
seg->size = size;
ret = insert_memory_segment(seg);
if (ret)
goto out_free;
ret = vmem_add_mem(start, size, 0);
if (ret)
goto out_remove;
goto out;
out_remove:
__remove_shared_memory(seg);
out_free:
kfree(seg);
out:
mutex_unlock(&vmem_mutex);
return ret;
}
/*
* map whole physical memory to virtual memory (identity mapping)
* we reserve enough space in the vmalloc area for vmemmap to hotplug
* additional memory segments.
*/
void __init vmem_map_init(void)
{
unsigned long ro_start, ro_end;
struct memblock_region *reg;
phys_addr_t start, end;
ro_start = PFN_ALIGN((unsigned long)&_stext);
ro_end = (unsigned long)&_eshared & PAGE_MASK;
for_each_memblock(memory, reg) {
start = reg->base;
end = reg->base + reg->size - 1;
if (start >= ro_end || end <= ro_start)
vmem_add_mem(start, end - start, 0);
else if (start >= ro_start && end <= ro_end)
vmem_add_mem(start, end - start, 1);
else if (start >= ro_start) {
vmem_add_mem(start, ro_end - start, 1);
vmem_add_mem(ro_end, end - ro_end, 0);
} else if (end < ro_end) {
vmem_add_mem(start, ro_start - start, 0);
vmem_add_mem(ro_start, end - ro_start, 1);
} else {
vmem_add_mem(start, ro_start - start, 0);
vmem_add_mem(ro_start, ro_end - ro_start, 1);
vmem_add_mem(ro_end, end - ro_end, 0);
}
}
}
/*
* Convert memblock.memory to a memory segment list so there is a single
* list that contains all memory segments.
*/
static int __init vmem_convert_memory_chunk(void)
{
struct memblock_region *reg;
struct memory_segment *seg;
mutex_lock(&vmem_mutex);
for_each_memblock(memory, reg) {
seg = kzalloc(sizeof(*seg), GFP_KERNEL);
if (!seg)
panic("Out of memory...\n");
seg->start = reg->base;
seg->size = reg->size;
insert_memory_segment(seg);
}
mutex_unlock(&vmem_mutex);
return 0;
}
core_initcall(vmem_convert_memory_chunk);